<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>背景颜色</title>
</head>
<body style="background-color: yellow">
  <h2 style="background-color: red">红色背景</h2>
  <p style="background-color: aquamarine">青色背景</p>
</body>
</html>